Over the past 20 years, the Internet has helped change our world in way or another for

Over the past four years, more than half of students in the high school caught receiving t

根据下列材料，请回答题Electronic MailDuring the past few years， scientists all over the wor

PC industry has developed rapidly all over the world during the past twenty years.

Increasingly over the past ten years the general

Increasingly over the past ten years people—especially young people—have become aware of

Over (the past) 20 years the Internet has (helped change) our world in (either) way or an